1,549 research outputs found
Approximation algorithms for stochastic and risk-averse optimization
We present improved approximation algorithms in stochastic optimization. We
prove that the multi-stage stochastic versions of covering integer programs
(such as set cover and vertex cover) admit essentially the same approximation
algorithms as their standard (non-stochastic) counterparts; this improves upon
work of Swamy \& Shmoys which shows an approximability that depends
multiplicatively on the number of stages. We also present approximation
algorithms for facility location and some of its variants in the -stage
recourse model, improving on previous approximation guarantees. We give a
-approximation algorithm in the standard polynomial-scenario model and
an algorithm with an expected per-scenario -approximation guarantee,
which is applicable to the more general black-box distribution model.Comment: Extension of a SODA'07 paper. To appear in SIAM J. Discrete Mat
Evanescent light-matter Interactions in Atomic Cladding Wave Guides
Alkali vapors, and in particular rubidium, are being used extensively in
several important fields of research such as slow and stored light non-linear
optics3 and quantum computation. Additionally, the technology of alkali vapors
plays a major role in realizing myriad industrial applications including for
example atomic clocks magentometers8 and optical frequency stabilization.
Lately, there is a growing effort towards miniaturizing traditional
centimeter-size alkali vapor cells. Owing to the significant reduction in
device dimensions, light matter interactions are greatly enhanced, enabling new
functionalities due to the low power threshold needed for non-linear
interactions. Here, taking advantage of the mature Complimentary
Metal-Oxide-Semiconductor (CMOS) compatible platform of silicon photonics, we
construct an efficient and flexible platform for tailored light vapor
interactions on a chip. Specifically, we demonstrate light matter interactions
in an atomic cladding wave guide (ACWG), consisting of CMOS compatible silicon
nitride nano wave-guide core with a Rubidium (Rb) vapor cladding. We observe
the highly efficient interaction of the electromagnetic guided mode with the
thermal Rb cladding. The nature of such interactions is explained by a model
which predicts the transmission spectrum of the system taking into account
Doppler and transit time broadening. We show, that due to the high confinement
of the optical mode (with a mode area of 0.3{\lambda}2), the Rb absorption
saturates at powers in the nW regime.Comment: 10 Pages 4 Figures. 1 Supplementar
Motivations for consulting complementary and alternative medicine practitioners: A comparison of consumers from 1997–8 and 2005
Background: Use of complementary and alternative medicine (CAM), and especially CAM
practitioners, has continued to rise in recent years. Although several motivators of CAM use have
been identified, little is known about how and if the motivations for using CAM have changed over
time. The purpose of the current study was to compare the reasons for consulting CAM
practitioners in consumers in 1997–8 and eight years later in 2005.
Methods: Surveys were displayed in CAM and conventional medicine offices and clinics in Ontario,
Canada in 1997–8 and again in 2005, and self-selected participants returned the surveys by mail.
Results: In 1997–8, 141 CAM consumers were identified from the 199 surveys returned, and 185
CAM consumers were identified from the 239 surveys returned in 2005. Five of the six CAM
motivations were more likely to be endorsed by the 2005 CAM consumers compared to the 1997–
8 CAM consumers (all p's < .0001). In 1997–8 the two top reasons for using CAM were that CAM
allowed them to take an active role in their health (51.8%), and because conventional medicine was
ineffective for their health problem (41.8%). In 2005, the treatment of the whole person (78.3%)
was the top reason for using CAM followed by taking an active role in one's health (76.5%). The
2005 consumers were less educated, had slightly more chronic health complaints, had been using
CAM for longer, and were more likely to consult chiropractors, reflexologists, and therapeutic
touch practitioners than the 1997–8 consumers. Otherwise, the socio-demographic and health
profiles of the two groups of CAM consumers were similar, as was their use of CAM.
Conclusion: Compared to consumers in 1997–8, consumers in 2005 were more likely to endorse
five of the six motivations for consulting CAM practitioners. A shift towards motivations focusing
more on the positive aspects of CAM and less on the negative aspects of conventional medicine
was also noted for the 2005 consumers. Findings suggest that CAM motivations may shift over time
as public knowledge of and experience with CAM also changes
Author correction : a global database for metacommunity ecology, integrating species, traits, environment and space
Correction to: Scientific Data https://doi.org/10.1038/s41597-019-0344-7, published online 08 January 202
Author correction : a global database for metacommunity ecology, integrating species, traits, environment and space
Correction to: Scientific Data https://doi.org/10.1038/s41597-019-0344-7, published online 08 January 202
Talking in primary care (TIP): protocol for a cluster-randomised controlled trial in UK primary care to assess clinical and cost-effectiveness of communication skills e-learning for practitioners on patients' musculoskeletal pain and enablement.
INTRODUCTION: Effective communication can help optimise healthcare interactions and patient outcomes. However, few interventions have been tested clinically, subjected to cost-effectiveness analysis or are sufficiently brief and well-described for implementation in primary care. This paper presents the protocol for determining the effectiveness and cost-effectiveness of a rigorously developed brief eLearning tool, EMPathicO, among patients with and without musculoskeletal pain. METHODS AND ANALYSIS: A cluster randomised controlled trial in general practitioner (GP) surgeries in England and Wales serving patients from diverse geographic, socioeconomic and ethnic backgrounds. GP surgeries are randomised (1:1) to receive EMPathicO e-learning immediately, or at trial end. Eligible practitioners (eg, GPs, physiotherapists and nurse practitioners) are involved in managing primary care patients with musculoskeletal pain. Patient recruitment is managed by practice staff and researchers. Target recruitment is 840 adults with and 840 without musculoskeletal pain consulting face-to-face, by telephone or video. Patients complete web-based questionnaires at preconsultation baseline, 1 week and 1, 3 and 6 months later. There are two patient-reported primary outcomes: pain intensity and patient enablement. Cost-effectiveness is considered from the National Health Service and societal perspectives. Secondary and process measures include practitioner patterns of use of EMPathicO, practitioner-reported self-efficacy and intentions, patient-reported symptom severity, quality of life, satisfaction, perceptions of practitioner empathy and optimism, treatment expectancies, anxiety, depression and continuity of care. Purposive subsamples of patients, practitioners and practice staff take part in up to two qualitative, semistructured interviews. ETHICS APPROVAL AND DISSEMINATION: Approved by the South Central Hampshire B Research Ethics Committee on 1 July 2022 and the Health Research Authority and Health and Care Research Wales on 6 July 2022 (REC reference 22/SC/0145; IRAS project ID 312208). Results will be disseminated via peer-reviewed academic publications, conference presentations and patient and practitioner outlets. If successful, EMPathicO could quickly be made available at a low cost to primary care practices across the country. TRIAL REGISTRATION NUMBER: ISRCTN18010240
Evaluation of macrophage migration inhibitory factor as an imaging marker for hepatocellular carcinoma in murine models
Objective. Macrophage migration inhibitory factor (MIF) is considered as an important mediator in the pathogenesis of neoplasia. The aim of the present study was to evaluate whether MIF could be used as a marker for hepatocellular carcinoma (HCC) detection. Material and methods. Biodistribution and whole-body autoradiography studies of 131I-labeled anti-MIF monoclonal antibody (McAb) and 131I-labeled control IgG were performed. The HCC-bearing mice were injected with 3.7 MBq of each agent and killed at 24, 48, and 72 h postinjection (p.i.). The organs, blood, and HCC tissues were removed from model mice, weighed, and counted using a gamma-counter. The expression of MIF mRNA and protein within HCC tissues was confirmed by RT-PCR and immunohistochemistry. Results. HCCs in model mice could be adequately visualized at 24 h p.i. The target-to-non-target (T/NT) ratios were 6.72 ± 1.09 (24 h), 9.85 ± 0.81 (48 h), and 12.31 ± 0.57 (72 h) for 131I-labeled anti-MIF McAb group, whereas in the control group of 131I-IgG, T/NT ratios were 4.65 ± 0.63 (24 h), 6.12 ± 0.60 (48 h), and 8.23 ± 0.35 (72 h) (p < 0.05). MIF mRNA expression was twofold higher in the HCC tissues than in the healthy liver tissues. MIF protein expression was much higher in the HCC tissues than in controls. Conclusions. Our findings suggested that 131I-anti-MIF McAb could be rapidly and specifically localized in tumors. Thus, MIF could be used as a marker for HCC tumor detection
Overexpression of endothelial nitric oxide synthase suppresses features of allergic asthma in mice
BACKGROUND: Asthma is associated with airway hyperresponsiveness and enhanced T-cell number/activity on one hand and increased levels of exhaled nitric oxide (NO) with expression of inducible NO synthase (iNOS) on the other hand. These findings are in paradox, as NO also relaxes airway smooth muscle and has immunosuppressive properties. The exact role of the endothelial NOS (eNOS) isoform in asthma is still unknown. We hypothezised that a delicate regulation in the production of NO and its bioactive forms by eNOS might be the key to the pathogenesis of asthma. METHODS: The contribution of eNOS on the development of asthmatic features was examined. We used transgenic mice that overexpress eNOS and measured characteristic features of allergic asthma after sensitisation and challenge of these mice with the allergen ovalbumin. RESULTS: eNOS overexpression resulted in both increased eNOS activity and NO production in the lungs. Isolated thoracic lymph nodes cells from eNOS overexpressing mice that have been sensitized and challenged with ovalbumin produced significantly less of the cytokines IFN-γ, IL-5 and IL-10. No difference in serum IgE levels could be found. Further, there was a 50% reduction in the number of lymphocytes and eosinophils in the lung lavage fluid of these animals. Finally, airway hyperresponsiveness to methacholine was abolished in eNOS overexpressing mice. CONCLUSION: These findings demonstrate that eNOS overexpression attenuates both airway inflammation and airway hyperresponsiveness in a model of allergic asthma. We suggest that a delicate balance in the production of bioactive forms of NO derived from eNOS might be essential in the pathophysiology of asthma
Phylogeny and Historical Biogeography of Asian Pterourus Butterflies (Lepidoptera: Papilionidae): A Case of Intercontinental Dispersal from North America to East Asia
The phylogenetic status of the well-known Asian butterflies often known as Agehana (a species group, often treated as a genus or a subgenus, within Papilio sensu lato) has long
remained unresolved. Only two species are included, and one of them especially, Papilio
maraho, is not only rare but near-threatened, being monophagous on its vulnerable hostplant, Sassafras randaiense (Lauraceae). Although the natural history and population conservation of “Agehana” has received much attention, the biogeographic origin of this group
still remains enigmatic. To clarify these two questions, a total of 86 species representatives
within Papilionidae were sampled, and four genes (concatenated length 3842 bp) were
used to reconstruct their phylogenetic relationships and historical scenarios. Surprisingly,
“Agehana” fell within the American Papilio subgenus Pterourus and not as previously suggested, phylogenetically close to the Asian Papilio subgenus Chilasa. We therefore formally
synonymize Agehana with Pterourus. Dating and biogeographic analysis allow us to infer
an intercontinental dispersal of an American ancestor of Asian Pterourus in the early Miocene, which was coincident with historical paleo-land bridge connections, resulting in the
present “East Asia-America” disjunction distribution. We emphasize that species exchange
between East Asia and America seems to be a quite frequent occurrence in butterflies during the Oligocene to Miocene climatic optima.© 2015 Wu et al. This is an open access
article distributed under the terms of the Creative
Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any
medium, provided the original author and source are
credited
The specificity and the development of social-emotional competence in a multi-ethnic-classroom
<p>Abstract</p> <p>Background</p> <p>Ethnic diversity in schools increases due to globalization. Thus, the children's social-emotional competence development must be considered in the context of a multi-ethnic classroom.</p> <p>Methods</p> <p>In this study, the social-emotional competence of 65 Asian-American and Latin-American children was observed at the beginning and the end of their kindergarten year.</p> <p>Results</p> <p>Initially, significant differences existed among these ethnic groups in respect to moral reasoning. Furthermore, the male children showed more dysregulated aggression but the female children implemented more moral reasoning than their male counterparts. These ethnic specificities did not disappear over the course of the year. In addition, a significant change in avoidance strategies as well as expressed emotions in the narrative took place over the course of one year.</p> <p>Conclusion</p> <p>Ethnic specificity in social-emotional competence does exist independent of gender at the beginning as well as at the end of the kindergarten year in a multi-ethnic kindergarten classroom.</p
- …